Head space analysis techniques are employed to analyze for volatile components in largely non-volatile mixtures. For example, this analytical technique is used in determining the amount of alcohol in a known quantity of blood. The technique is also used for analyses of volatile components in other body fluids. Further applications include analysis of trace organic compounds in water samples, testing for the presence of solvents in drugs, for solvents or monomers in polymers, for fragrances in toiletries, for flavors or aromas in foods, and the like. It is desirable in these applications to have a transport device capable of transporting samples automatically at high rates to the analyzing instrument. It is also desirable for the transport device to be able to be programmed to automatically repeat the sampling of one or more vials one or a number of times. This feature is useful for improving the precision of the analysis.
The amount of volatile components in the gaseous headspace portion over a liquid sample in a closed vial is known to vary with the temperature of the liquid sample. Therefore, it is very important to maintain the temperature of the liquid sample within a very narrow range in the transport prior to analysis. Further, because the actual quantity of material in the headspace over a liquid sample is very small, any contamination from outside sources would substantially alter the analysis of the headspace gases. Therefore, the risk of outside contamination must be minimized during the sampling process. Also, because sample vials are made in various sizes, it is desirable that the transport device be able to accommodate different sizes.